Oven.



No. 804,943. v PATENTED NOV. 21, 1905.

, W. M. FULTON.

OVEN.

APPLICATION IILED HOV. 2,1904.

2 SHEETS-SHEET 1.

PATENTED NOV. 21, 1905.

W. M. FULTON.

OVEN.

APPLIOATION FILED NOV. 2, 1904.

2 SHEETS-SHEET 2.

UNITED STATES PATENT. OFFICE.

WESTON M. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTON COMPANY, OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

vented a new and useful Improvement in 'ing, cooking, and similar operations.

Ovens, which invention is fully set forth in the following specification.

This invention relates to improvements in ovens, and especially to such ovens as bakeovens, hot-air and steam baths, in which it is desirable to maintain a uniform temperature by controlling the supply of the heating agent.

Heretofore attempts have been made to devise means for maintaining uniform temperatures in heating-chambers whereby a predetermined temperature could be maintained for a continued period of time without attention by an attendantsuch, for example, as in the culture of yeast and bacteria, in dry- The means heretofore usually employed, which havedepended upon the principle of expansion for controlling the supply of heating medium, have included such materials as clay and metal rods, mercury, and liquids of high boilingpoints. The dilficulty with such expansible substances is that their coefficients of expansion are not 'uniform for all temperatures, and

devices using such means require careful calibration and continued attention and control and often with uncertain results.

It is the object of this invention to overcome the above objections and to provide a heatingchamber whose temperature can be regulated and controlled by the expansion and contraction of a gas or gaseous fluid operating through suitable means the fluid-supply for heating and whereby slight changes in the temperature of the chamber effect a quick and positive control of the supply of fluid to the I burner.

It is a further object to provide a heatingchamber the interior of which can be readily inspected without danger of causing fluctua: tions of temperature which may affect the operations in the chamber, and, further, to

provide aneconomical structure simplein construction, sensitive, and positive in its action To this end I make use of the well-known principle that for equal volumes of gases and vapors at temperatures above the boilingpoints of their liquids when heated each takes on substantially equal increments of volume for equal increases of temperature. In other Specification of Letters Patent. Application filed Novem er 2, 1904. Serial NUT-231,119.

Patented Nov. 21, 1905.

In applying this principle I confine or vapor and gas within a collapsible and expansible vessel, such as described in my United States Patent No. 685,269, and provide suitable connecting neans between the vessel and the valve in the fuel-supply pipe, whereby for each degree rise of temperature there will be the same amount of linear expansion of the collapsible vessel and of similar uniform movement of the valve. 7 This increment for each degree will be very large, because all the increase of volume of the confined gas manifests itself in linear extension of the vessel. Two results are secured by reason of such construction. The expansion of the gas in the vessel being uniform for each degree, the

companying drawings, which are. designed. merely as lllustrations to asslst 1n the descr1ption of the invention and not as defining the limits thereof.

In said drawings, Figure l is a perspective View of one form of my improved device. Fig. 2 is a vertical sectional view thereof. Fig. 3 is a detail of a modification. Fig. 4 is a. view of the indicator-card and index, and Fig. 5 is a detail.

Referring to the drawings, 1 is an inner chamber or oven arranged within an outer casing 2 and having an air-space 3 provided therebetween. The walls of chamber 2 arie made thick and preferably are provided with heatlaggin'g material, such as mineral wool, so as to avoid loss of heat to the outside atmosphere by conduction. are located one or more shelves 4, on which the artidles to be treated, contained in suitable vessels, if necessary, are placed. There is also arranged within chamber 1 a collapsible and expansible vessel or regulator 5 of the type heretofore referred to, provided with rigid end walls, one of which is shown at 9,

Within chamber or oven1 Fig. 1, and charged with one or more gaseous bodies which are hermetically sealed therein. The regulator or vessel 5is supported within the oven by means of a frame 6, attached to a tube '7, one end of which passes through both walls of the chambers and terminates in a brace 8, which is fast to outer casing 2,

where it is securely held. To give additional support for frame 6, it may also be made fast to the shelf 4. One of the end walls of the vessel 5--as, for example, the left-hand wall shown in Fig. 2is madefast to the frame 6, while the opposite end wall 9 is free'to move. Attached to wall 9 of the collapsible and expansible vessel is a small rod 10, which extends through the supporting-tube 7 to the outside of theouter casing 2 and terminates in a ball-socket 11. Located in socket 11 is a ball 12,.provided with a rod 13, which is furnished with turning means, such as a handwheel 14, Fig. 2. A portion of rod 13 is screw-threaded and carries a traveling nut 15. (See Fig. 3.) Revolubly connected to this nut 15 is an arm 16, keyed to the valve-stem of valve 17, located in fuel-supply conduit 18, supported in bracket 8.

At the base of the oven is placed heating means, such as an oil or gas burner 19. As shown in Fig. 2, this burner is supported in a casing or hood 20, which is adapted to slide in ways 21, enabling its ready removal. In the form of oven provided with an air-space and shown in Figs. 1 and 2 it is preferable to conduct theproducts of combustion or hot-air currents around the inner casing, thereby secu ring greater efficiency in heating. To this end openings 22 and'23 are provided in the outer .casing, the one, 22, for introducing the heated gases and the other, 23, for permitting their escape. When a fluid or gas burner is employed, a shield 24 is interposed between the top of the burner and the bottom of the oven A to prevent the corrosionof the oven-Wall. In

the doublewalled type of oven herein described, which is especially adapted for carrying on the growth of cultures, it is desirable to inspect the interior without, exposing the contents of the oven and without reducing its For this purpose double doors are provided 'an outer door 25, ofsuitable heat-insulating material, such as asbestos, andan inner door 26, made of-transparent material, such as glass or mica. In case the valve 17 should be turned too far, and thereby cut' off the fuel-supply, a by-pass is provided, such as a groove 27, cut around the cone-plug 28, Fig. 5. Other means, such as a pilot-flame, would be equally serviceable in preventing complete cut-off.

The operation of the device as thus far described is as follows: The hand-wheel 14 is turned in the proper direction to force the nut 15 to the left, thereby opening the valve 17 in the fuel-conduit 18. The ball-and-socket joint 12 and 11 permits of the slight displacedle 31.

ment of the rod 13 during the rotation of the latter. The burner 19 is then lighted and placed in position under the oven. The prodnets of combustion circulate around the inner oven and heat its contents, causing the vessel 5 to expand, thereby forcing the head 9 to the right, and with it the rod 10, connected to the arm 14, which acts to close the valve 17 Complete extinction of the flame is, however, prevented by reason of the supply of gas around the valve-stem 28 through groove 27. As the atmosphere of the oven cools the vessel,5 contracts and draws the arm to the left, thereby opening the fuel-supply valve. It is evident that a temperature will soon be reached where the supply of gas admitted to the burner is just sufficient to maintain a fixed temperature within the oven. Ifcold materials are placed within the oven, reducing its temperature, the wall 9 moves to the left, thus opening the valve 16, and thereby admitting more fuel to the burner 19. If it is desired to maintain a higher temperature in the oven, the wheel 14 is turned to cause nut to move to the left, thereby admitting more gas to the burner 19. The regulator 5 will then have to expand further to close valve 17than before, and for this reason a higher temperature will be required in the oven to cause the regulator to reduce the gas-supply. Likewise, in order to reduce and maintain a lower temperature wheel 14 is turnedto move nut 15 to the right. This form of oven is especially useful in fermenting yeast and yeast culture, where it is desirable to exclude products of combustion.

When it is desirable to change the temperature of the oven often, the gas-valve and its operating devices may be inclosed in a hood. This construction is illustrated in Fig. 3, in which 29 is the casing of the hood, and 30 is a dial-face. The valve-operating shaft 13 in this case is provided at its outer end with a han- The shaft of hand-wheel 32 extends through the dial 30 and carries a'depending arm 33, provided with a slot through which arm 31 of the valve-operating arm 13 loosely extends. Traveling over the dial, is an index 34, fast to the shaft of hand-wheel 32. In

Fig. 4 is shown an enlarged view of the dial graduated to temperatures found useful in the culinary art. A stop 35 .is preferably placed on the dial to prevent turning the index beyond the limits of adjustability. In using the dialzthe index is moved to the temperature indicated on the dial and desired to be maintained in the oven. This movement of the index is also transmitted by arm 33 to handle 31 of the shaft 13, carrying the nut 15, which sets the valve for the requisite supply of fuel to the burner.

Although a double-wall oven has been described to illustrate the invention, it is not intended'to limit it to this particular form, as it is applicable to ovens of single-wall and of other forms. The burner may also be placed inside the oven, as in thecase of a bake-oven, Where the products of combustion are not deleterious to the operations going on therein.

What is claimed isv 1. In combination, aheating chamber, acasing surrounding the same and's'eparated therefrom, an expansible and collapsible vessel located-therein and containing a gaseous fluid, a" rigid support extending from the wall of the heating-chamber and fast to one end of said vessel, a fuel-supply pipe leading to the heating-chamber, a valve in the supply-pipe, provided with an operating'lever-arm, a valveactuating rod connected to the movable end of said vessel; 'an adjusting screw-threaded rod engaging said lever-arm and having a actuating rod;

- flexible revo'luble connection with said valve- 2. In combination, a heating-chamber, an

expansibleand collapsible vessel therein containing a gaseous fluid, a rigid support for one end of said vessel, a fuel-supply pipe, a

-- valve therein havinga' lever-arm, a valveactuating member connected to the movable end of said vessel, an'adjusting-rod engaging said lever-arm, 'a flexible revoluble connection between said adj usting-rodand valve-actuat- The contour of the oven may be; round, square, or other shape and of any desired material. i

ing" member and rotating and registering means attached to said adjusting-rod.

' 3. In combination, aheating-chamber, a Gas, ing surrounding the same and separated therefrom, an expansible and collapsible vessel therein containing a gaseous fluid, a rigid support for one end of said vessel, a valved fuelof said vesselbeing free to move .under the action of temperature changes, a valved fuelsupply pipe, a valve-actuating rod housed in said support and fast to the movable end of said vessel and having a flexible adjustable connection with said valve.

Intestimony whereof I have signed this specification in the presence of two subscribing Witnesses.

WESTON M. FULTON.

Witnesses:

JOHN S; BROWN, W. W. BERRY. 

